Drag type is quite obvious it is the state of the drag the player is trying to use
From container getDragEvent which is called in Container#onSlotClick
/**
* Args : clickedButton, Returns (0 : start drag, 1 : add slot, 2 : end drag)
*/
ClickType is whether the player is shift clicking, or drag clicking etc. Look at ClickType.
And the other to are the same so...